Mobile-service providers already possess and operate several heterogeneous access technologies and networks. The mixed-networks environments are expected to become more prevalent as different radio technologies best serve different deployment types and environments. For example, Wi-Fi™ has shown to be a great technology for indoor operation, whereas cellular technologies, such as 2G/3G (2nd Generation/3rd Generation) and WiMAX (Worldwide Interoperability for Microwave Access) operate best in licensed spectrum covering large outdoor environments. It is also expected that multi-mode wireless devices shall become widespread. Hence, it is of great interest to the mobile operators, technology users, and vendors to provide seamless mobility between these heterogeneous access technologies with uninterrupted service continuity.
The current technologies have focused on pure layer 3 (L3) mobility solutions, such as Mobile IP (Internet Protocol). Although, these technologies support an inter-access mobility solution, the handoff delay could be extremely high. Furthermore, such L3 mobility procedures rely completely on the mobile device to make a handoff decision. These solutions rely on dual-radio operation, i.e., both the radios involved in handover would be transmitting at the same time. This, however, may not always be possible, because due to interference, platform noise and/or co-existence issues, we might only have a single radio operating at any point in time.
This disclosure proposes an alternative architecture to support a Single-Radio Handover solution leading to tighter handover control and synchronization and overall lower latency of handovers and packet loss.